From 72b57bef7b0e7e3bae7ef607a05435d8fa115c31 Mon Sep 17 00:00:00 2001
From: Julien TINNES <julien@cr0.org>
Date: Thu, 27 Aug 2009 15:26:58 +0200
Subject: ipv4: make ip_append_data() handle NULL routing table

commit 788d908f2879a17e5f80924f3da2e23f1034482d upstream.

Add a check in ip_append_data() for NULL *rtp to prevent future bugs in
callers from being exploitable.

Signed-off-by: Julien Tinnes <julien@cr0.org>
Signed-off-by: Tavis Ormandy <taviso@sdf.lonestar.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 net/ipv4/ip_output.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 3e7e910c7c0f..d1d88e6255bc 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -814,6 +814,8 @@ int ip_append_data(struct sock *sk,
 			inet->cork.addr = ipc->addr;
 		}
 		rt = *rtp;
+		if (unlikely(!rt))
+			return -EFAULT;
 		/*
 		 * We steal reference to this route, caller should not release it
 		 */
-- 
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